1. 前期準備
在叢集中使用rsh實現無密碼訪問，首先要做的工作是在所有節點的/etc/hosts檔案中寫入所有的主機地址與名稱（最好所有主機的系統、核心都是相同的，本文所有測試工作在Centos 7.3，3.10.0-514.26.1.el7.x86_64上進行）。例如：

/etc/hosts

127.0.0.1 localhost
192.168.1.100 manage
192.168.1.101 compute1
192.168.1.102 compute2

2. 安裝rsh和rsh server（rshd）

yum install rsh rsh-server

3. 開啟rsh服務

    法一：通過systemd services

• 設定rsh服務為允許啟動

            setup→system services→systemed services→[*]rsh.socket[*]rlogin.socket[*]rexec.socket 

• 允許rsh服務自啟

	[[email protected] ～]# /usr/bin/systemctl enable rsh.socket
	[[email protected] ～]# /usr/bin/systemctl enable rexec.socket
	[[email protected] ～]# /usr/bin/systemctl enable rlogin.socket
 

• 配置rsh server

            編輯/etc/securetty，加入rsh，rexec，rlogin（在檔案後面新增就可以）（不按此修改，會提示輸入密碼。但是即使使用者名稱與密碼正確也將無法登陸）。

• 重啟rsh服務

	[[email protected] manage ～]# systemctl restart rsh.socket
	[[email protected] manage ～]# systemctl restart rlogin.socket
	[[email protected] manage ～]# systemctl restart rexec.socket
 

    法二：rsh屬於xinetd服務，可以通過xinetd來啟動

• 確認服務
  

進入/etc/xinetd.d目錄，如果檔案rsh、rlogin、rexec不存在，則新建如下；如果存在，根據以下內容修改。

	/etc/xinetd.d/rsh
	# default: on  
	# descrīption: The rshd server is the server for the rcmd(3) routine and, \  
	#       consequently, for the rsh(1) program.  The server provides \  
	#       remote execution facilities with authentication based on \  
	#       privileged port numbers from trusted hosts.  
	service shell  
	{  
	        disable = no  
	        socket_type             = stream  
	        wait                    = no  
	        user                    = root  
	        log_on_success          += USERID  
	        log_on_failure          += USERID  
	        server                  = /usr/sbin/in.rshd  
	}  
	  
	/etc/xinetd.d/rlogin  
	  
	# default: on  
	# descrīption: rlogind is the server for the rlogin(1) program.  The server \  
	#       provides a remote login facility with authentication based on \  
	#       privileged port numbers from trusted hosts.  
	service login  
	{  
	        disable = no  
	        socket_type             = stream  
	        wait                    = no  
	        user                    = root  
	        log_on_success          += USERID  
	        log_on_failure          += USERID  
	        server                  = /usr/sbin/in.rlogind  
	}  
	  
	/etc/xinetd.d/rexec  
	  
	# default: off  
	# descrīption: Rexecd is the server for the rexec(3) routine.  The server \  
	#       provides remote execution facilities with authentication based \  
	#       on user names and passwords.  
	service exec  
	{  
	        disable = no  
	        socket_type             = stream  
	        wait                    = no  
	        user                    = root  
	        log_on_success          += USERID  
	        log_on_failure          += USERID  
	        server                  = /usr/sbin/in.rexecd  
	}  

• 配置rsh server

            編輯/etc/securetty，加入rsh，rexec，rlogin（在檔案後面新增就可以）（不按此修改，會提示輸入密碼。但是即使使用者名稱與密碼正確也將無法登陸）。

• 重啟xinetd服務

[[email protected] ~]# /sbin/service xinetd restart

4. rsh無密碼訪問配置

當root使用者試圖使用rsh時，將驗證/root/.rhosts檔案，而如果是普通使用者將驗證/etc/hosts.equiv檔案。需要修改每個主機的這兩個檔案（保持一致）：

manage
compute1
compute2

5. 測試

[[email protected] ~]# rsh compute1
Last login: Sun Mar 18 00:43:20 from manage
[[email protected] ~]# rsh manage
Last login: Sun Mar 18 00:53:31 on compute1
[[email protected] ~]# rsh compute2
Last login: Sun Mar 18 00:53:43 from manage
[[email protected] ~]# rsh manage
Last login: Sun Mar 18 00:54:00 from compute2